1. Field of the Invention
The present invention relates to a sheet feeding apparatus used in facsimile machines, printers, copying machines, and the like for separating a plurality of sheet media such as originals and recording paper into individual sheets and transporting the same.
2. Description of the Related Art
In recent years, facsimile machines, printers, copying machines, and the like have been coming into widespread use even in homes and development of smaller sized and lower priced ones is demanded. FIG. 9 is a side view schematically showing an example of a conventional article. Sheet feeding apparatus 110 shown in the drawing is what is disclosed in Japanese Utility Model Registration No. 3045808 and it has sheet feed roller 120 for delivering sheet 200. Above this sheet feed roller 120, there are disposed pressure structure 130 being a plate spring for pressing sheet 200 against sheet feed roller 120 and separation structure 140 for separating the one sheet that is in contact with sheet feed roller 120 from a plurality of sheets in a stack, which are about to be transported by sheet feed roller 120, and allowing the one sheet to be fed into sheet feed roller 120.
Separation structure 140 is made up of flexible separation pad 141 made of rubber, silicone, or the like and plate spring 142 for pressing separation pad 141 against sheet feed roller 120.
The position where pressure structure 130 is in contact with sheet feed roller 120 is located upstream the sheet feeding direction from the position where separation pad 141 is in contact with sheet feed roller 120, i.e., forwardly of that position with respect to the rotating direction of sheet feed roller 120. Therefore, a plurality of sheets 200 transported from sheet supply tray 150 toward sheet feed roller 120 are pressed, at their ends, against sheet feed roller 120 by pressure structure 130 and, hence, the plurality of stacked sheets tend to be fed forward with the rotation of sheet feed roller 120. Since separation structure 140 separates only one sheet in contact with sheet feed roller 120 from sheets 200 in the stack, only the one sheet 200 is fed downstream the sheet feeding direction with the rotation of sheet feed roller 120.
In conventional sheet feeding apparatus 110, however, when a plurality of sheets 200 are inserted with a rush from sheet supply tray 150 toward sheet feed roller 120, the plurality of sheets 200 that are stacked are fed into the position where separation pad 141 and sheet feed roller 120 are in contact and, hence, they are inserted between separation pad 141 and sheet feed roller 120. Thus, there has been a multipicking problem that a plurality of stacked sheets 200 are fed out from sheet feed roller 120.
The present invention has been made to avoid the multipicking by a sheet feed roller even when a plurality of sheets in a stack are rushed to be inserted. Accordingly, the invention comprises a pressure plate rotatably supported so as to be separated from a sheet feed roller by a force applying thereto when sheets are inserted and a first resilient member acting so as to bring the pressure plate into contact with the sheet feed roller and it, further, comprises a rotatable separation plate disposed downstream the sheet feeding direction from a pressure portion where the sheet is pressed against the sheet feed roller and a second resilient member for pressing the separation plate in the direction of the sheet feed roller.